Expansion joint and bridge joint seals

ABSTRACT

Invertible, elongated, elastomer joint sealing strips having substantially flat sidewalls, longitudinally corrugated or pleated top and bottom walls preferably of the same general configuration, and an internal web structure with one or two pairs of crossed webs connected to the top and bottom walls and additional diagonal webs extending diagonally across the four corners to provide two or three side-by-side diamond openings in internal structure of seals.

United States Patent Delmont D. Brown;

Donald R. Boney, both of North Baltimore, Ohio May 21, 1969 June 22, l97l The D. S. Brown Company North Baltimore, Ohio Inventors Appl. No. Filed Patented Assignee EXPANSION JOINT AND BRIDGE JOINT SEALS 6 Claims, 4 Drawing Figs.

U.S.Cl 94/18 lnLCl Elllc 11/10 FleldolSearch 94/l8,39,

[56] References Cited UNITED STATES PATENTS 3,276,336 10/1966 Crone.... 94/18 3,358,568 l2/l967 Brown 94/18 3,455,2l5 7/1969 Webb 94/ i8 Primary Examiner-Jacob L. Nackenofi' Attorney-Johnston, Root, O'Keeffe, Keil, Thompson and Shurtlefi' ABSTRACT: lnvertible, elongated, elastorner joint sealing strips having substantially flat sidewalls, longitudinally corrugated or pleated top and bottom walls preferably of the same general configuration, and an internal web structure with one or two pairs of crossed webs connected to the top and bottom walls and additional diagonal webs extending diagonally across the four comers to provide two or three side-by-side diamond openings in internal structure of seals.

PATENTEU JUN22 197:

sum 2 or 2 DELMONT DONALD R -b zr vwwam EXPANSION JOINT AND BRIDGE JOINT SEALS BACKGROUND OF THE INVENTION The sealing strips of the subject invention are designed primarily for use in joints having a relatively large width dimension and a substantial amount of joint movement. Expansion joints and bridge joints are the two better known types of such joints. Expansion joints are formed transversely or crosswise in a pavement or highway the full depth of the slab. They are provided to allow the concrete to expand as it becomes heated under the warmer climate conditions and/or sun radiation. The temperature of concrete in highways or other pavements such as airport runways, concrete drainage ditches, and the like may vary from temperatures in the order of or -30? F. in the winter months up to temperatures in the range of 130 to 140 F. in the summer months. Over such temperature range, the concrete has considerable amount of contraction and expansion.

To allow for such expansion or contraction, transverse joints or spaces are provided at defined intervals. These joints or spaces must be sealed in order to prevent accumulation of undesired particles such as sand, gravel or other incompressibles in an amount whereby such accumulation prevents the joint from closing by expansion of the concrete in warm weather. Joints are also sealed in order to prevent infiltration of water, the freezing of which in cold weather can cause damage to the joint. In supported joints, e.g., joints having a dowel-type supporting structure across the joint, infiltration of water can cause rusting or other damage to the dowel structure. Also, water entering the joint can also cause, in some instances, washing away and erosion of the subgrade in the area of the joint.

The joints of bridges with which the subject invention is primarily concerned are joints on the decks or floors of bridges. The filling of such joints with incompressibles is undesirable for the reasons aforesaid. Additionally, water, particularly water carrying dissolved deicing chemicals such as calcium chloride or sodium chloride, can be damaging to concrete and/or steel understructures of the bridge if it is allowed to flow through the deck or floor joints of the bridge.

In some highway designs, expansion joints are used in combination with contraction joints, e.g., in an arrangement of relatively widely spaced expansion joints and a plurality of contraction joints therebetween. Contraction joints allow pavement slabs to expand only to their original length. They do not accommodate relatively high orders of expansion of the concrete sections between the contraction joints with the result that some highways are designed to include expansion joints periodically in addition to the contraction joints to take up expansion of pavement which cannot be accommodated by the contraction joints between two expansion joints.

It has been proposed heretofore by others to seal expansion joints and/or bridge joints with elongated, elastomer joint sealing strips having an internal web truss structure which, in the laterally collapsed or compressed state of the sealing strips, urges the sidewalls of such strips against the sidewalls of the joints to provide the requisite sealing of such joints. Illustrative thereof are the sealing strips illustrated in US. Pat. Nos. 3,358,568 and 3,276,336.

BRIEF DESCRIPTION OF THE INVENTION Briefly, the present invention concerns elongated, elastomer joint seals which are particularly adapted for use in relatively wide joints having substantial amounts of joint movement. These sealing strips are characterized by longitudinally corrugated or pleated top and bottom walls which fold into pleats when the strip is laterally compressed. These top and bottom walls are substantially symmetric and preferably of substantially identical configuration, one being the substantial mirror image of the other. This provides an invertible scaling strip wherein either of said walls can constitute the upper or top wall. Thus, should one of these walls be damaged during installation or after the seal has been in service, the seal may be removed and inverted so that the undamaged wall serves as the top wall of the seal.

The seals of the subject invention are further characterized by an internal web structure of elastomer webs which allow a great range of lateral collapse of the seal between the minimum width dimension of the seal where the internal webs are pressed tightly against each other and the maximum width dimension of the seal, i.e., one in which the seal is compressed to a width of about percent to percent of the uncompressed width of the seal.

The internal web structure comprises a set of diagonal webs which provide one or two Xs substantially at the center portion of the seal and which connect at their respective longitudinal edges either directly or via narrow vertical connecting strips with the top and bottom walls at longitudinal juncture lines which are laterally inwardly of the respective corners of the seal. The internal web structure further has additional webs extending diagonally across the four comers from the respective longitudinal juncture lines at the top and bottom walls or from the narrow connecting strips to respective intersections with the midportions of the sidewalls.

The top and bottom walls, respectively, may have the shape of a shallow W and a shallow M to provide the aforesaid pleated shape. With one type seal, the midpart of the top wall is a shallow M, the edges of the latter being connected to the sidewalls by more steeply diagonal top wall segments. The bottom wall is the same shape in mirror image. The sidewalls preferably are substantially flat or planar. The sidewalls and top and bottom walls may be joined at the four corners of the seal by rounded comers, the purpose of which is set forth in more detail below.

DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention is illustrated in the drawing wherein:

FIG. 1 is a perspective view of a fragmentary end section of the embodiment;

FIG. 2 is an end elevation of an expansion joint with the seal of FIG. I mounted therein in the laterally compressed state;

FIG. 3 is a perspective view of another embodiment of an elastomer joint sealing strip; and

FIG. 4 is a perspective view of a third embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, the elongated, hollow elastomer seal 10 comprises sidewallsll and 12 which are preferably substantially parallel, elongated, substantially flat or planar, elastomer walls. The longitudinal edges of the sidewalls 11 and 12 are joined with the top wall 13 and bottom wall 14 by integrally formed rounded corners 15, 16, 17 and 18. Though less preferred, such corners may be sharp comers.

The top wall 13 has a shallow W shape formed by longitudinally elongated, transversely diagonally downwardly extending side segments 19 and 20 and longitudinally elongated, transversely diagonally upwardly extending center segments 21 and 22 which meet at a central apex 23.

The bottom wall 14 is a shallow M-shaped wall made up of longitudinally elongated, transversely upwardly extending side segments 25 and 26 and longitudinally elongated, transversely diagonally downwardly extending center segments 27 and 28 which meet at a central, inverted apex 29.

When the seal is laterally collapsed, the side segments 19, 20, and 25, 26 fold downwardly and inwardly (FIG. 2) while the center segments 21,22 and 27,28 assume respective sharp inclinations. Such orientation raises and lowers the respective apices 23 and 29 relative to the rounded comers [5-18.

The internal web structure comprises a set of diagonal webs 3033 which join and are integral at the juncture 34 in the center of the seal. The web pairs 30,31 and 32,33 form an X configuration with the respective longitudinal edges of the X integral and joined with the nadirs and apices 35-38 of the respective outer and center segments of the top and bottom wall.

The remainder of the internal web structure comprises longitudinally elongated, transversely diagonal webs 39, 40, 42 and 43 which cut diagonally across the four corners of the seal. The diagonal web 39 is joined with and is integral with the nadir 35 at one longitudinal edge and with the midportion 41 of the sidewall 11 at the other longitudinal edge. The diagonal web 40-is joined with and integral with the midportion 41 and the apex 37. The diagonal web 42 is joined with and integral with the nadir 36 and the longitudinal midportion 44 of the sidewall 12, while the diagonal web 43 is joined with and integral with the longitudinal midportion 44 and the apex 38. It is not essential for purposes of the invention that the diagonal web pairs39,40 and 42,43 meet at a common juncture as illustrated. If desired, these webs may meet the respec tive sidewalls 11 and 12 at spaced intersections rather than at the longitudinal midportions 41 and 44.

As shown in FIG. 2, the internal webs do not form sharp bends or folds when the seal is laterally compressed. This is a distinct advantage in that sharp ends or folds, particularly those approaching 180, impart high stresses to the web structure. Such bends or folds would form when the seal is in its maximum state of compression, Le, a state of compression when the joint is most closed. This state occurs in the hot summer months when the concrete reaches temperatures over 100 F. The higher temperatures are more detrimental to aging of the elastomer whereby it loses its resilient properties. Experience indicates that elastomer seals in field use can be expected to lose up to 50 percent of their initial resilient characteristics in a period of one to three years. High stresses in any of the elastomer webs or walls materially accelerate the aging degradation of the elastomer and hence it is of considerable advantage to avoid sharp bends.

As shown in FIG. 2, the crossed webs 30-33 substantially retain their X configuration when the seal is laterally collapsed. This characteristic is the result of the overall geometry of the seal whereby the sidewalls 11 and 12 in effect become somewhat longer upon lateral compression of the seal while the outer segments of the top and bottom walls 19,20 and 25,26 become somewhat shorter through a rolling action of the rounded corners 15l8.

Because of the aforesaid characteristics of the seal, it is preferred that the central apices 23 and 29 in the uncompressed seal be respectively lower and higher than the upper comers 15 and 18and the lower corners 16 and 17. In such arrangement the apices 23 and 29 rise and drop, respectively, to positions which do not extend appreciably above or below the respective corners of the seal when the latter is laterally collapsed (see FIG. 2).

As the width dimension of the subject seals increases, it is desirable to keep the angle of the diagonal internal members from becoming too flat with respect to the horizontal. Preferably such angles should never be less than about 30 and most optimally they are in the order of 40 to 50. Therefore, the diagonal rib members may be connected to the top and bottom walls and/or to each other by means of narrow, vertical, integral, elastomer strips such as shown in FIGS. 3 and 4.

Referring first to FIG. 3, this hollow, elongated, elastomer seal 50 of the subject invention includes a pair of sidewalls 51 and 52 which are preferably substantially planar and substantially vertically disposed. The top and bottom walls 54 and 55 have a projected width greater than the depth of the sidewalls 51 and 52, e.g., as in a seal having a depth of 3 V4 inches and a width of 5 inches.

The top wall 54 comprises two sharply downwardly sloping outer sections or strips 56 and 57 and a shallow-M-shaped midpart composed of the inner, downwardly converging legs 58 and 59 and outer, downwardly diverging legs 60 and 61.

The bottom wall 55 is a mirror image of the top wall 54 whereby the sealing strip can be inverted 180. The bottom wall comprises the outer, sharply upwardly sloping sections or strips 56 and 57' and the shallow-W-shaped midpart composed of the legs 5861. The respective midparts are preferably below the junctures of the sidewalls and top and bottom walls forming the comers 62 so that their apices 63 and 63' do not rise above the outer corners of the seal when the seal is collapsed laterally.

The internal web structure of the sealing strip 50 is composed of diagonal webs 64, 65, 66 and 67 in the right-hand portion of the strip and a similar set of diagonal webs 69, 70 71 and 72 in the left-hand portion of the strip. The right-hand webs 64-67 meet and are joined by a narrow, vertically disposed web segment 68 and the longitudinal edges of the webs 69-72 are similarly joined by a narrow vertical web 68.

The upper and lower longitudinal edges, respectively, of the webs 64,71 and 66,70 are joined with a nadir and a apex of the top and bottom walls 54 and 55 by similar, vertically disposed, narrow webs 73 and 73.

The remainder of the internal structure of the sealing strip 50 comprises diagonal webs or ribs 74, 75, 76 and 77 extending diagonally across the corners 62 of the sealing strip 50. They are joined respectively with the diagonal ribs or members 67, 65, 69 and 72 by narrow, vertically disposed, webs 78 and 78', the latter in turn connecting these diagonal internal members with the top and bottom walls respectively at the nadirs and apices 79 and 79' formed by the outermost strips or segments and next adjacent segments of the midportions of these walls.

As in the embodiment of FIGS. 1 and 2, the internal webs do not form sharp bends or folds when the seal is laterally compressed, the advantages of which have been described above. The use of the narrow webs 68, 68', 73, 73', 78 and 78' allow the diagonal, internal webs 6467, 69-72 and 7477 to extend transversely diagonally at the optimum angle with reference to the horizontal, i.e., an angle of about 40-50, to give the maximum lateral thrust effect when they are collapsed or bent as the seal 50 is collapsed laterally. The crossed webs 64-67 and 6972 substantially retain their approximate X configuration when the seal is laterally collapsed. This characteristic is the result of the overall geometry of the seal, which allows for some vertical flexure in the midportions of the top and bottom walls 54 and 55. Because of the aforesaid characteristics of the seal, it is preferred that the midportions in the uncompressed seal be respectively lower and higher than the corners 62. In such arrangement the midportions may rise and drop, respectively, to positions which do not extend appreciably above or below the respective corners of the seal when the latter is laterally collapsed.

The sealing strip 80 of FIG. 4 is similar in some respects and different in other respects from the sealing strips 50. It has a vertical dimension which is substantially equal to the width dimension. It comprises a pair of vertically disposed, substantially parallel sidewalls 81 and 82 with top and bottom walls 83 and 84. The top wall 83 is, in transverse cross section, in the shape of a shallow W, while the bottom wall 84 is substantially a mirror image thereof in the shape of a shallow M in transverse cross section. The top wall 83 comprises downwardly sloping outer segments 85 and 86 and shallow, inverted V- shaped inner segments 87 and 88. The bottom wall 84 comprises upwardly sloping outer segments 89 and 90 and shallow V-shaped inner segments 91 and 92.

The diagonal, inner members of the sealing strip 80 comprise rib members 93 and 94 which are substantially coplanar and rib members 95 and 96, which are also substantially coplanar. These rib members cross at about the longitudinal axis of the seal and together form an X. The outer edges of the X are connected by diagonally sloping rib members 97 and 98 and 99 and 100, which respectively intersect in pairs at substantially the midportion of the sidewalls 81 and 82. The rib members 93-100 are connected to the nadirs and apices of the top and bottom walls by narrow, vertically disposed connecting strips 102, 104, 106 and 108, which respectively intersect and merge with the valleys 101 and 105 and apices 103 and 107 of the top and bottom walls 83 and 84.

As in the other embodiments, the embodiment of FIG. 4 provides diagonal, internal webs which do not form sharp bends or folds when the seal is laterally compressed. In all embodiments, these diagonal webs form in the seals a plurality,

Le, two or three, side-by-side, diamond-shaped or substantially diamond,shaped cavities surrounded by substantially triangular, trapezoidal and/or symmetrical hexagonal cavities formed by portions of the outer walls of the hollow seals and diagonal webs.

The seals of the subject invention should be made of good quality elastomer formulations in order that these seals retain their elastic properties with aging under environmental conditions. To this end, the elastomer composition should be an elastomer formulation which is extrudable, and which, upon vulcanization, will be resistant to deterioration and/or loss of resilience after exposure to hot and cold weather conditions, sunlight, and like elements of nature in the use thereof in joints of pavement, air strips, and the like. The preferred elastomer therefore is neoprene, preferably the crystallization-resistant-types thereof.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. An elongated, elastomer, joint-sealing strip comprising an elongated hollow body defined by substantially planar sidewalls, a top wall of substantially shallow W-configuration, a bottom wall of substantially shallow M-configuration, the nadirs of said W-configuration of the top wall being opposite the apices of said M-configuration of the bottom wall, a pair of diagonal webs connected to the nadirs of the top wall and to the apices of the bottom wall and crossing at the centers thereof, and additional diagonal webs connected respectively to said nadirs and apices and the midportions of contiguous sidewalls.

2. A joint-sealing strip as claimed in claim 1 wherein said top wall and bottom wall are joined respectively with said sidewalls by rounded corners.

3. A joint-sealing strip as claimed in claim 1 wherein said diagonal webs are joined at their longitudinal edges directly to said apices and nadirs and also to said sidewalls.

4. A joint sealing strip as claimed in claim 1 wherein said diagonal webs are joined at their longitudinal edges directly to the sidewalls and by narrow, vertical, elastomer webs to said top and bottom walls.

5. An elongated, elastomer,joint-sealing strip comprising an elongated hollow body defined by substantially planar sidewalls, a top wall having a midportion of shallow-M-configuration with the edges of said midportion joined with the sidewalls by upwardly sloping strips, a bottom wall having a midportion of shallow-W-configuration with the edges of the latter midportion joined with said sidewalls by downwardly sloping strips, the three nadirs and two apices of said top wall being respectively opposite the three apices and two nadirs of the bottom wall, two pairs of diagonal web structures crossing at the centers thereof and extending diagonally from the nadirs of the top wall to the apices of the bottom wall, and additional diagonal webs extending from the two outer nadirs of said top wall and the two outer apices of the bottom wall to the midportion of contiguous sidewalls.

6. A joint-sealing strip as claimed in claim 5 wherein said additional diagonal webs are joined at their longitudinal edges directly to said sidewalls, and said additional webs and said webs of said pairs are joined to said apices and nadirs by narrow, vertical webs. 

1. An elongated, elastomer, joint-sealing strip comprising an elongated hollow body defined by substantially planar sidewalls, a top wall of substantially shallow W-configuration, a bottom wall of substantially shallow M-configuration, the nadirs of said W-configuration of the top wall being opposite the apices of said M-configuration of the bottom wall, a pair of diagonal webs connected to the nadirs of the top wall and to the apices of the bottom wall and crossing at the centers thereof, and additional diagonal webs connected respectively to said nadirs and apices and the midportions of contiguous sidewalls.
 2. A joint-sealing strip as claimed in claim 1 wherein said top wall and bottom wall are joined respectively with said sidewalls by rounded corners.
 3. A joint-sealing strip as claimed in claim 1 wherein said diagonal webs are joined at their longitudinal edges directly to said apices and nadirs and also to said sidewalls.
 4. A joint sealing strip as claimed in claim 1 wherein said diagonal webs are joined at their longitudinal edges directly to the sidewalls and by narrow, vertical, elastomer webs to said top and bottom walls.
 5. An elongated, elastomer, joint-sealing strip comprising an elongated hollow body defined by substantially planar sidewalls, a top wall having a midportion of shallow-M-configuration with the edges of said midportion joined with the sidewalls by upwardly sloping strips, a bottom wall having a midportion of shallow-W-configuration with the edges of the latter midportion joined with said sidewalls by downwardly sloping strips, the three nadirs and two apices of said top wall being respectively opposite the three apices and two nadirs of the bottom wall, two pairs of diagonal web structures crossing at the centers thereof and extending diagonally from the nadirs of the top wall to the apices of the bottom wall, and additional diagonal webs extending from the two outer nadirs of said top wall and the two outer apices of the bottom wall to the midportion of contiguous sidewalls.
 6. A joint-sealing strip as claimed in claim 5 wherein said additional diagonal webs are joined at their longitudinal edges directly to said sidewalls, and said additional webs and said webs of said pairs are joined to said apices and nadirs by narrow, vertical webs. 